Until Eternity
by ariathal2410
Summary: Mana's found his soulmate and he's really not sure what to do about it. So of course, he turns to the only person he can. Soulmate AU, Modern AU, Familial Soulmates


**WARNINGS:** Mentions of past abuse, mention of minor character death, kind of angsty?

 **AN:** Little oneshot to help me get back into writing. Soulmate AU in which the name of your soulmate is written somewhere on your body. Familial soulmates for the win.

* * *

Mana listened to the drone of the phone as it rung. He worried for a moment that it wasn't going to go through. The line finally clicked and his brother's noncommittal hum greeted him. He chuckled.

"Hey Neah." Mana said softly. He didn't need to say anything else.

"Mana!" Neah's surprise was palpable. Mana thought he heard a pen drop. "It's been a while since you called, I was worried. Is everything okay?" Neah couldn't call him. Mana didn't have a phone. He was sitting in a rundown alley, using a payphone that probably had more bacteria on it than a toilet seat. _Ew_. Mana squirmed.

"I'm okay… Sort of… I don't know…" He paused, tried to find the right words. "I'm stressed." Mana could practically hear his twin's frown.

"Something happened." It wasn't a question. Mana hummed. How to phrase this? He stared at the child in front of him, playing with whatever he could get his hands on, trying to create new tricks with random objects he found in the alley.

"I found my soulmate." Mana said eventually. "He's ten." Neah spluttered on the other end of the phone.

"He's _what_?" Incredulity, confusion, _concern_. Mana understood. He was concerned too. He didn't know how to take care of a child, he could barely take care of himself. Somehow though, _somehow_ , he'd made it work. So far. At least, Allen hadn't complained. Yet.

"Ten. He's ten. I adopted him. Sort of…" Why was this so hard to explain? "I picked him up off the streets a couple of years ago. At a circus. The ringmaster was abusive. He _killed my dog_. I didn't want him to kill the kid too, so I took him with me when I left. And no, I wasn't really thinking straight at the time, before you ask. Anyway, I only just found out he was my soulmate, so I thought I'd tell you." He stopped to take a shaky breath. He watched the child in front of him. He'd found a pipe, and was currently trying to balance it on his head. _Cute._

Mana was terrified, if he was being honest with himself. Allen had become more and more important to him over the past two years, but now he was his _soulmate_. Mana thought he might actually die if anything happened to the child. Because Allen had been _so good_ for him. Mana had never dealt well with being alone. Neah would live with him if he asked, he _knew_. But he also knew his brother could come to resent him for it. He had suffered at the hands of their father, to the point where he could barely stay in the same place for more than a year. He hated being chained down, hated being _bound_. Mana wouldn't do that to him. While he himself moved around a lot, it was more out of listlessness than any actual desire. He didn't know what else to do. He was always restless. He didn't have anywhere to call home anymore. It affected him more than he'd like to admit.

Now, though, now he had Allen. And while the child might be slightly violent and rather foul-tempered, he was Mana's. Right from the start. It had been rocky at first, the man wouldn't deny that. But he had chosen Allen, and the boy had liked that more than he would ever admit. So he had stayed with Mana, and now he clung to the man like the child he was. Mana adored him. It was ridiculous really, how attached he had gotten in the space of a mere two years. But Allen was his. And Mana was Allen's. And as it turns out, they really were. Soulmates. He should've noticed earlier. Probably would have if Allen hadn't been so traumatised. The boy didn't like turning his back on anyone. Pressing his back against Mana was fine. That was _safe_. But turning around where he couldn't see people? That wasn't something the boy did. He refused to change in the same room as Mana too. So it had been a rather large surprise when the child had bared his back of his own volition, to get Mana to read the name inscribed there.

"I didn't realise he was my soulmate at first… Cos I named him, you know? So I didn't notice that it changed." He rambled, trying to figure out why he'd really called his brother. He tried to swallow down the sudden lump in his throat. "I don't know what to do…" _I don't want to mess this up_. He didn't say. His brother would know anyway. Neah sighed. He heard paper crumpling, and for a moment he worried. Had his brother been sleeping? Was he eating? Was he clean? Was he _safe_? Mana had these bouts of worry sometimes, and they often ended in long conversations with his brother. Which was good for both of them sometimes. Neah sighed again, and this time Mana thought it was more fond than anything. Which was weird. Maybe his mind was playing tricks on him? Allen had crawled into his lap at this stage, scowling at him because it was cold outside. And maybe a little bit because he was worried.

"Where are you? We'll figure this out together." Neah said, and Mana hadn't heard his voice that soft in a long time. Not since they were teenagers. Not since they still had hope for their futures. Not since their mother had died.

"I don't want to bother you…" Mana said it so quietly. He was half hoping Neah wouldn't hear. His brother sighed once more. Loud and frustrated.

"For someone with such a high IQ you're dumb as a sack of rocks sometimes, you know that?" Mana made a noise. He wasn't sure what it meant though. A protest maybe? Neah continued anyway. "You're my brother, dumbass. _I love you_. Christ." There was some other mutterings, but Mana didn't quite catch them. He was too busy trying not to cry. And trying to convince Allen that he didn't need to _murder_ who he was on the phone with for _making_ him cry.

"Okay." Mana agreed eventually, a wobbly sound if anything else. "I love you too." Because he _did_. And he felt like Neah needed to know that. Needed to _hear it_ more than he did.

"Okay." Neah said with finality. "Where are you? It'll probably be easier for me to come to you." Mana froze. He looked at the streets around him, at the diner across the road, and the little hotdog stand on the sidewalk.

"Umm…" He had literally no idea what city he was currently in.

" _Mana._ " Neah growled.

* * *

 **AN:** Neah's absolutely sick of his brother's irresponsible bullshit, but he'll help him regardless, cos he loves him. Sap. Anyway, I was just thinking about soulmate's, and how they're not necessarily always romantic, and then I was thinking that Mana and Allen would _definitely_ be familial or platonic soulmates.

 **Omake:** _Mana's a dumbass A.K.A. How he found out Allen's his soulmate._

For as long as Mana could remember, the mark on his back had said _Red._ He had been confused, and rightfully so. What kind of name was Red? He grew up daydreaming about whether his future soulmate was going to be a singer, like Cher, or Madonna, or maybe an actor, like Zendaya. And later, when he was older and more distraught, he thought that maybe his soulmate was in an abusive household too, so they'd decided to drop the surname. He'd never given up his own though, because it was his mother's, and he'd be damned if he let his father take that away from him too.

When he'd met Allen, the boy had told him flat out that he didn't have a name. Not one that he used, anyway. So Mana had named him. _How else is your soulmate supposed to find you?_ Allen Walker. He supposed it shouldn't have really been a surprise that the name on his back changed too. Unfortunately, Mana hadn't looked at his back in a long time. Hadn't felt the desire to for too long. At that stage in his life, he'd given up on ever finding his soulmate. He felt that he'd failed. That he didn't deserve a soulmate, or his brother. Then he'd found Allen. And everything was slightly okay. And he found an all new reason not to worry about the name on his back. As long as he had Allen, everything would be fine.

He really was stupid sometimes, wasn't he?

He found out on a lazy winter afternoon. It was cold outside (-3°C cold), so there wasn't really anyone around to watch them perform. He didn't want to make Allen go out in that weather if he didn't have too, so he'd used a bit of their spare money to get a dingy motel room for the night. Allen was tumbling around on the floor, practising his acrobatics, as much for the sake of keeping warm and occupied as it was for actually practising. Mana was watching. Sort of. He was staring into space part of the time, making sure Allen wasn't getting hurt part of the time, and counting all the health code violations in the room for the rest of it. There was a lot.

After a while, Allen stopped. Whether because he was bored or getting tired, Mana didn't know. He did know when Allen kicked him in the shin in a demand for attention. They settled on the dusty floor, and Mana helped Allen with his reading and writing, humming the song he'd made with his brother. He'd teach Allen that too. Allen stopped soon, looked up at him. He stared at him for a while. And Mana was nothing if not patient. He waited, smiling calmly, fondly. Allen scratched his back, under his shirt. That little slip just above his left hip that he always played with when he was frustrated or worried. He squinted at Mana a moment longer, then twisted. Mana's eyebrows shot up as the child lifted the back of his shirt, fingers itching the black scrawl of his soulmark.

"What does it say?" Allen asked gruffly, eyes still squinted in Mana's general direction. Mana tried not to cry. This was so important. _So important_. He gave Allen a wobbly smile, and the child huffed, rolled his eyes. His cheeks were dusted pink, and he scratched his soulmark again. So that was it. He scratched his soulmark when he was anxious. _So cute._ Mana scooted forward a little, leaned down so he could see better.

 _Mana D. Campbell._

.

.

.

 _What…?_ Mana sat up straight and stared at the wall for a solid ten seconds. He'd just read his own name on Allen's skin. He looked down at the child's soulmark again. Back to the wall. Then he twisted. Pulled up his own shirt and squinted at the writing on his back, in the exact same place as Allen's. It took him an unreasonably long time to decipher.

 _Allen Walker_.

It was a childish scrawl, like it always had been, but the name was very much _different._ Mana took a deep breath. Let it out.

" _Oh_." He breathed. Allen stared up at him like he had two heads.


End file.
